Originally Posted by
J. Greg Jones
I don’t know who first discovered this technique, nor do I think it really matters. [edited]
It was probably discovered by the first person to cut dovetails and realized the mark was not in the waste but in the area of the pin that was to be retained.
Many likely understood this and cut to the waste side of the line. Then along came those who figured a few tools and a bit of salesmanship could make them some money.
jtk
"A pessimist sees the difficulty in every opportunity; an optimist sees the opportunity in every difficulty."
- Sir Winston Churchill (1874-1965)